What do you think is wrong in my blocks? (SIMPLE ALARM/NOTIFICATION)

The application doesnt execute even after the time and date is set.

use Do it to debug your blocks, see tip 4 here App Inventor: How to Learn | Pura Vida Apps
you might have to first add time and date and check that in the Clock.Timer event

Taifun

May i ask is there a specific block that i can use to redirect to screen 1 after clicking the notification alarm? For example, the application alarms, then the user will click it and it will redirect to the application.

kodular apps are not working in background yet, like you want that app to show a notification or alarm and that all work is happening in app, but when you close app, all works will be stop,

you are using the Simple Notification extension, which opens Screen1 of your app after pressing the notification. You probably have to exit the app after sending the notification for this to work.
You might want to read the documentation and try the example project…
Taifun